Thanks very much for the feedback, but I'm still in the dark on a number of points:

1. In response to Bentgear, I'm using stick built ailerons & tail instead of the kit slabs...the kit tail/aileron is slab-built (just 1/4" slabs with some holes cut in), not stick built, so I'm hoping to save weight/increase strength ....I'm also hoping to use carbon for the tail-braces, instead of the supplied steel, and with both of the above weight advantages, I hope to have the opportunity of mounting a servo or two down the tail....any comments?

2. Also, agreed, the saito 56 is light, but it's considerably longer than an equivalent 2 stroke, so I thought that for both esthetic as well as CG reasons, I might move it back some, to place it's mass where it ought to be... and so that it looks right

I agree also with Paul Carnes that a 56 maybe a little under-powered, but it's a start and since the mounting holes are identical to a saito 72...I can always upgrade to the monster... when the monster calls

Silversurfer makes an interesting point about high G/ high load situations, (so maybe I'll leave well enough alone)... but most of those forces are acting on the aluminium wing tube, that is to say, transferred from the wing surfaces via the spars through the first couple of ribs onto the cardboard phenolic impregnated female tube and onto the aluminium tube....If this is correct (and I'm not sure that it is), I don't see why the root ribs can't have holes fore and aft, at a respectable distance from the main wing-tube assembly. Any comments?

All comments welcome and many thanks for those already offered